Rock-drill.



WITNESSES M. E. THOMAS.

ROCK DRILL.

APPLICATION mm) 1330.7, 1910 1,026,886. Patented May 21,1912.

d lNVENTOR,

ortrrr. s'rntrns P ENT oFFIoE.

ROCK-DRILL.

Specification of Letters Patent.

Patented Ma 21,1912.

Application filed December 7, 1910. Serial No. 596,155.

all whom it may concern:

tie it known that I, M'An'rm E. THOMAS, a itizen of the United States, residing at it sling Green, in the county of \Varren and State of Kentucky, have invented a new and useful Rock-Drill, of which the follow log 5 a specification.

iis invention has reference to improvements in rock drills, and more especially tor the drilling of coal or other like cornparutively s oft material, and its object is to provide a readily removable and renew able head and cutters for a coal drill, whereby the twisted shanks of drills already in use may be utilized and the head may be readilychanged from one shank to another where shanksof difierent lengths are used without the necessity of providing each shank with a head.

In the present invention there is provided a head of solid construction readily adapted to drill shanks already in use with a mini. mum of change in the structure of the shank, the change being of a character readily made by an ordinary blacksmith, while each head has a suitable set of rotary cutters in interacting relation, whereby a bore may be re. idly cut, and in case of the breakage or du ling of the cutters. any one or all of them may e readily replaced by new sharp cutters, the operation requiring only a tool adapted to the removal of a bolt. .The entire head, or, if desired, the cutters only, are readily transportable in an ordinary miners kit. The head is utilized as a carrier for feeding wings designed to carry the cuttings .or chippings ot' the cutters back to the conveyor twist of the drill shank.

The, invention will be best mulcrstood from a consideration of the following do tailed description taken in connection with the accompanying drawings forming a part of this specification, with the understanding, however, that while the showing of the drawings is that of a practical embodiment oi. the invention, the latter is not confined to the exact disclosure of the drawings, but may be variously modified without material departure from the salient features of the invention.

In the drawings :-F igure 1 is a side view of a drill with the head attached thereto.

Fig. 2 is an end view of the head of the drill. Fig. 3 1s a rear view of the head of 'LHLMAS, OF BOWLING GREEN, KENTUCKY, ASSIGNDR F THREE-FOURTHS "f ELLIS W. HESTER AND BALI'JY P. BELK, 0F BOWLING G BEEN, KENTUCKY.

the drill detached from the shank of the i drill and with the feeding sleeve omitted.

Fig. 4 is a section on the line 4-4 of Fig. 2.

Fig. 5 is a detail view of a portion of the 3 into which may be fitted a tapered end 4 of the shank 1, the socket being appropri atcly tapered to receive this tapered shank, and the socket and shank are provided with passages so located as to match when the shank is within the socket, and a pin 5 serves to secure the head 2 to the drill shank The end of the head 2 re-' mote from the socket 3 is formed with lugs t) which in the instance shown are three in number and project in a general radial dircctiou to the longitudinal axis of the head, and each log is set at an angle to the longitudinal axis and to the cutting plane of the head and, also, at an angle to the other lugs, so that one end of each lug is directed forwardly and outwardly with reference to the direction of rotation about; the longitudinal axis of the head. llach lug has opposite plane faces parallel one to the other and is provided with a perforation perpendicular to said faces "for a bolt 7, the head of which confines a disk cutter 8 directly against the outer face of the lug, so that each cutter is presented to the material to be cut at an angle of about titty-three degrees, although such angle is not mandatory, but is found in practice to answer the purpose of the invention. The body of the head 2 adjacent the rear face of each lug may be undercut as indicated at 9 to accommodate a nut 10 on the end of the respective bolt 7, but the depth of this undercut and its presence at all will depend upon the size of the drill head. The cutters 8 are shown as of -cir O gitudinal cular form with curved faces merging into a peripheral edge constituting the cutting edge, and these cutters are mounted to turn upon their supporting bolts, so as to rotate 5 upon, their individual axes during the operation of the drill and are alsocaused to traverse an orbital path about, the longitudinall axis of the drill as a whole.

The planes of the 0 several cutters are at such an angle one to the other that they will intersect at the central longitudinal axis of the cutter head it the latter'be projected a short distance beyond the front edge of the gutter head in '15 the direction of travel of the butter into the material being operated upon. lVith cutters disposed as shown in the drawings, their active portions will extend from the most advanced points in the direction of the lonaxis of the cutter head back to a point approximately at right tngles to the forward portion of the cutter, so that the activecutting edge at any one time embraces nearly or quite ninety degrees of the circumference of the cutter. The cutter, therefore, because of its large active extent works rapidly into such material as coal. Atthe same I time, the lugs 6 and head 2 may be made massive enough to-readily withstand all the strains under which they may be placed in the operation of cutting, and will withstand any strains without breakage or distortion Which will be withstood by the cutters themselves, or by the twisted shank of the drill '35 body. Moreover, since the projection of the shanks oi? the bolts beyond the lugs is only that of the thickness of the cutting disks, such bolts will readily withstand all strains to which they may be subjected without it 40 being necessary to make them unduly massive.

The socket portion 3 is made substantially square exteriorly and adapted to this square port-ion isa square sleeve 11 having formed on opposite sides inclined wings 12, these wings being preferably so positioned as to extcnd diagonally across the corresponding face of the sleeve at an angle approximating the angle of the twisted portions of the drill shank or body, and the pitch of these wings is in the same direction as the pitch ofthe twisted portions of the drill body, so that cuttings or chippings removed from the cutters 8 are caught by the wings 12' and conveyed into operative relation to the twisted portion of the shank to be carried by the latter to the mouth of the bore and there discharged. The same pin 5 utilized to se-' cure the drill head to the shank may be made of sufficient length to extend through cutting edges of the l matching holes in the sleeve 11 to thereby hold this sleeve to the exterior of the socket 3 against escape therefrom. There is no danger-of shearing this pin since there is no relative movementbetween the taper por tion 4: of the shank 1 and either the socket 3 or the sleeve 11, sinceythese several parts may be made to fit quite snugly and their form will prevent any relative rotation about the longitudinal axis of the drill.

In the adaptation of the present'inventi-on to drill shanks already in use wherein the head of the drill is usually made integral with the shank thereof after the manner of an ordinary anger, the taper end 4 may be readily formed by a blacksmith and fitted to the soeket 3. Where the invention is applied to ,new drill shanks, the integral head is omitted and the twisted body is supplied initially with a tapered end 4. The change of the head from one drill shank to another, or the renewal of the cutters is readily broughtabout by the miner without" the necessity of sending the drill to the repair shop and without the necessity of having the several drills of different lengths each pro-- vided with a head individual thereto.

For all ordinary purposes three cutters disposed in a circular seriesiatone hundred and twenty degrees apart will be found, well adapted for the purpose, but the invention is not necessarily confined to the number of cutters shown.

What is claimed is:- 4

A cutter head provided at its active end with a circular series of integral and sub-- stantially radial lugs with opposite plane faces parallel one to the other and inclined to the longitudinal axis of the cutter head, the end of the cutter head remote from the lugs being formed into a socket with the exterior Walls substantially parallel with the longitudinal axis of the socket, rotatable cutting disks one for each lug and mounted on that face of the lug toward the active face of the cutter head, the axis of rotation of the cutting disk being perpendicular to the corresponding face of the lug, and a sleeve provided with externally inclined materialdirect-ing wings and having an internal bore conforming to the external form of the socket end of the cutter head.

In testimony, that I claim the foregoing as my own, I have hereto afiixed my signature in the presence of two witnesses.

MARTIN E. THOMAS. Witnesses:

V. E. Trsnnr, V. SADLnR. 

